Process for the preparation of resins with a primary amine or guanidine function, and resins thus obtained

ABSTRACT

The process includes the reaction of a chloro-formamidinium chloride with a polystyrene-divinylbenzene resin functionalized with primary amine groups. The resins which can be obtained according to this process may in particular have a spacer arm of general formula (IV): ##STR1## with X representing oxygen or sulphur and m being equal to 1 or 2. This spacer arm bears at its end, on the right, a primary amine group or a guanidine group.

This is a division, of application Ser. No. 08/764,017 filed Dec. 11,1996, now U.S. Pat. No. 5,726,253.

BACKGROUND OF THE INVENTION

The present invention relates to a process for the preparation of resinsbased on polystyrene-divinylbenzene which are functionalized withprimary amine or guanidine groups, and to novel resins which can beobtained by the use of this process.

These resins are used as bases, in particular as basic catalysts inliquid/solid heterogeneous phase reactions.

A process is known from U.S. Pat. No. 5,340,380, which consists insubstituting the chlorine of a chloromethyl polystyrene-divinylbenzeneresin with a substituted or unsubstituted guanidine and which makes itpossible to obtain resins of general formula (A): ##STR2## representsthe starting solid polystyrene-divinylbenzene resin support it beingpossible for R₁, R₂, R₃ and R₄ each to be a hydrogen, an alkyl group oran aromatic group.

Thus, U.S. Pat. No. 3,346,516 describes this technique offunctionalization by reaction of a chloromethylpolystyrene-divinylbenzene resin with gruanidine or tetramethylguanidinein the presence of a lower alcohol and a solvent for swelling thecopolymer such as tetra-hydrofuran, dioxane or diglyme.

In U.S. Pat. No. 5,028,259, the tetramethyLguanidine is placed incontact with a chloromethyl polystyrene-divinylbenzene resin in amixture of toluene and tetrahydrofuran.

In U.S. Pat. No. 5,340,380, guanidines are reacted with chloromethylresins of this same type in the presence of sodium hydroxide in asolvent consisting of ethanol or water.

Moreover, S. V. Luis, M. I. Burguete and B. Altava, Reactive &Functional Polymers, 26, 1995, 75-83 indicate that the readychloromethylation of polystyrene resins and the high reactivity of theresulting benzyl sites allows the introduction of a large number offunctional groups and explains the widespread use of these polymers. Onthe other hand, these authors comment that the reduced length of themethylene spacer arm reduces the mobility on the functional groupsintroduced and, in certain cases, makes it difficult for reactants,substrates and solvents to gain access to them. This situation may leadto a decrease in the activity of the functional groups when they arecompared with their soluble correspondents. In certain cases, a markedimprovement in the activity of these groups bound to the resin has beenobtained when the active site is separated from the polymer skeleton bya suitable spacer arm. S. V. Luis et al. prepare polystyrene resinshaving spacer arms in the form of a linear aliphatic chain containing 6or 9 methylene groups and bearing a hydroxyl group --OH at the end ofthe chain. This hydroxyl group is converted into a tosylate leavinggroup, the latter being replaced by substitution with a tertiary aminegroup.

In this synthesis, S. V. Luis et al. use functionalization of thepolystyrene resin by a Friedel Crafts type reaction using the acidchloride derived from a monoalkyl ester of an alkanedioic acid.

This synthesis has the major drawback, of reducing both a tosylhydrazonegroup and an ester group by the double hydride LiAlH₄ in tetrahydrofuraTHF. This reduction makes this synthetic route unattractive in terms ofa large-scale industrial development of resins containing these --(CH₂)₆-- or --(CH₂)₉ -- spacer arms.

Other authors have become interested in producing spacer arms in theform of a methylene chain. Thus, M. Tomoi, N. Kori and H. Kakiuchi,Reactive Polymers, 3, 1985, 341-349, introduce a long aliphatic chainonto polystyrene resins by alkylation with ω-bromoalkenes in thepresence of trifluoromethanesulphonic acid.

However, this synthesis is limited to the preparation of polymers with aspacer arm which have a low degree of crosslinking (0-4%).

Starting with a chloromethyl polystyrene resin, G. D. Darling and M. J.Frechet, J. Org. Chem., 51, 1986, 2270-2276 have, for their part,obtained a --(CH₂)₂ -- spaer arm which separates the resin fram ahydroxyl --OH at the end of the chain. This hydroxyl is converted, intotosylate and then, via the Gabriel reaction using potassium phthalimideand lastly hydrazine, into primary amine. However, this synthesis hasthe drawback of using n-butyllithium or lithium aluminium hydride.

SUMMARY OF THE INVENTION

A principal object of the present invention is to propose a process forthe preparation of resins based on polystyrene-divinylbenzene (PS-DVB),functionalized with guanidine groups, this process needing to be readilyindustrializable for the production of theese resins in large amounts.This process must be general and must make it possible in particular toproduce resins with spacer arms which allow the guanidine functions tobe spaced from the resin support by at least one methylene group.

Another object of the present invention is to provide PS-DVB resinsequipped with spacer arms which are longer than a methylene group. Thesynthesis of these resins thus functionalized needs to be simple forindustrial production and in particular needs to avoid the use ofreactants of the butyllithium or lithium aluminium hydride type.

Upon further study of the specification and appended claims, furtherobjects and advantages of this invention will become apparent to thoseskilled in the art.

The principal object of the invention is achieved by a process for thepreparation of resins based on polystyrene-divinylbenzene (PS-DVB) whichare functionalized with guanidine groups, characterized in that itcomprises the following steps:

(1) providing a PS-DVB resin functionalized with a primary amine groupthis resin being of general formula (I): ##STR3## wherein: ##STR4## isthe PS-DVB resin support, and L is a linear organic radical at least aslong as methylene (--CH₂ --),

(2) reacting a chloroformamidinium chloride (Vilsmeier salt) with theresin (I) in the presence of a base, this chloride being of generalformula (II): ##STR5## wherein R₁, R₂, and R₃ are, independently of eachother, chosen from the methyl, ethyl, propyl, butyl, cyclohexyl andphenyl groups, to obtain a PS-DVB resin functionalized with a guanidinegroup and of general formula (III) ##STR6## wherein: ##STR7## L and R₁to R₄ have the same meanings as above.

The PS-DVB resins with a primary amine function of general formula (I)may be obtained by various techniques.

(1) it is possible, for example, to start with a resin of generalformula (B): ##STR8## X being a leaving group, in particular halogen ortosylate obtained from hydroxyl group --OH, and L having the samemeaning as above. Preferably, when L represents a single methylene, X isa chlorine atom. In this case, a method, described by D. H. Rich and S.K. Gurwara, J. Am. Chem. Soc., 97, 1575-1579, 1975, consists in reactinga chloromethyl PS-DVB resin with excess ammonia. Another route is basedon the production of phthalimidomethyl PS-DVB resin, which is convertedby hydrazinolysis into a resin with a primary amine function. Twomethods for producing such phthalimidomethyl resins are described in thepublication by A. R. Mitchell, S. B. H. Kent, B. W. Erickson and R. B.Merrifield, Tetrahedron Letters No. 42, 1976, 3795-3798. One consists instarting with a PS-DVB resin which, on reaction withN-(chloromethyl)phthalimide, is directly converted intophthalimidomethyl resin. The other method starts with a chloromethylPS-DVB resin which is treated with potassium phthalimide to give thecorresponding phthalimidomethyl resin. The latter method is alsoapplicable to resins of formula (B) in the case where L is a linearorganic radical longer than the methylene radical, in particular--(CH₂)_(n) -- with n being equal to an integer greater than 1.

(2) It is also possible to start with a PS-DVB resin of formula (B) inwhich L represents a methylene and X has the above meaning andpreferably represents a chlorine atom. For example, the chloromethylresin is reacted with an alkanolamine, in alkaline alkoxide form, underthe Williamson reaction conditions.

If ethanolamine is used, PS-DVB resins having a primary amine functionwith --CH₂ --O--CH₂ --CH₂ --NH₂ functional groups bound to the PS-DVBresin supports are obtained.

If 2-(2-aminoethoxy)ethanol is used, PS-DVB resins having a primaryamine function with --CH₂ (O--CH₂ --CH₂)₂ --NH₂ functional groups boundto these supports are obtained.

Similarly, starting with 2-aminoethanethiol hydrochloride, --CH₂--S--CH₂ --CH₂ --NH₂ functional groups are obtained.

Lastly, using 2-[(2-aminoethylthio]ethanethiol, --CH₂ --(S--CH₂ --CH₂)₂--NH₂ functional groups are obtained.

This starting mercaptoalkylamine may be prepared according to Iwakura etal., J. Polym. Sci. Part A, 2, 1964, 881-883 or according to I.Voronkov, M. G. et al., Chem. Heterocycl. Compd. (Engl. Transl.)15,1979, 1183-1185.

Thus, the following intermediate PS-DVB resins may be obtained:

A resin based on PS-DVB, characterized by its general formula (I):##STR9## wherein: ##STR10## is the PS-DVB resin support, L representsthe radical of general formula (IV):

    --CH.sub.2 --(--X--CH.sub.2 --CH.sub.2 --).sub.m --        (IV)

X represents oxygen --O-- or sulphur --S-- and m equals 1 or 2.

Advantageously, X represents oxygen and m is equal to 1.

Advantageously, X represents sulphur and m is equal to 1.

These intermediate resins bearing a primary amine group at the end ofthe chain may be used as basic catalysts in chemical reactions inheterogeneous medium.

The general conditions of the Williamson reaction are as follows:

The alkanolamine or the mercaptoalkylamine diluted in anhydroustetrahydrofuran (THF) is reacted with sodium hydride suspended inanhydrous THF. After formation of the sodium alkoxide or the sodiummercaptide, the chloromethyl resin is introduced into the liquidreaction medium.

The PS-DVB resins used as starting materials in the present inventionare obtained in a known manner by copolymerization of styrene with DVBas crosslinking agent. The DVB is used at weight contents ranging from0.5% to 60% relative to the total weight of PS plus DVB.

With a low content of DVB (0.5 to 7%), copolymers in the form of gelsare obtained, whereas with higher DVB contents, macrocrosslinked resinsof macroporous type may be obtained. Such resins are commerciallyavailable.

These PS-DVB resins may be chloromethylated with chloromethyl ether,according to known techniques which are described in the literature, tovariable chlorine (--Cl) contents, generally from 1 to 20% by weight ofchlorine relative to the weight of chloromethyl resin.

The resins with terminal guanidine functions of general formula (III)are obtained by reaction of chloroformamidinium chlorides of generalformula (II) with the PS-DVB resins of general formula (I).

The chloroformamidinium chlorides (II) are generally obtained fromtetrasubstituted ureas by reaction with electrophilic compounds such asphosgimne, thionyl chloride, oxalyl chloride or phosphorus oxychloride,according to methods described in the literature, in particular:

COCl₂ H. Eilingsfeld, M. Seefelder, Angew.Chem., 72, 1960, 836.

SOCl₂ H. Ulrich, A. A. R. Sayigh, Angew. Chem. Intern. Ed. Engl., 5,1966, 704.

(COCl)₂ T. Fujisawa et al., Chem. Lett., 1982, 1891.

POCl₃ H. Bredereck, K. Bredereck, Chem. Ber., 94, 1961, 2278.

Generally, stoichiometric amounts of tetrasubstituted ureas and ofelectrophilic chloro compounds are used at the start and the process isperformed in the presence of a solvent such as carbon tetrachloride inthe case of oxalyl chloride, or without solvent with phosgene or thionylchloride, at a temperature generally of from 0° C. to 40° C., and underan anhydrous atmosphere to prevent any hydrolysis.

The tetrasubstituted ureas are advantageously chosen fromtetramethylurea, tetraethylurea, tetra-n-propylurea andtetra-n-butylurea.

The chloroformamidinium chlorides (II) are generally placed in a solventsuch as toluene or acetonitrile. Their reactions with the resinscontaining a primary amine function (I) are carried out in the presenceof a base, preferably in the presence of an excess of base.

If the base is triethylamine (TEA), the process is generally performedwith a molar excess of TEA of from 10 to 50% relative to thechloroformamidinium chlorides (II). The latter are generally in a molareccess of from 10 to 100% relative to the number of moles of primaryamine function, in order to convert all of the latter into guanidinefunctions.

In the process according to the invention, L may represent a methylene--CH₂ --.

Advantageously, L represents the radical of formula (IV)

    --CH.sub.2 --(--X--CH.sub.2 --CH.sub.2 --).sub.m --        (IV)

in which X represents oxygen --O-- or sulphur --S-- and m is equal to 1or 2.

Preferably, in the formula (IV), X represents oxygen and m is equal to1.

Preferably also, in the formula (IV), X represents sulphur and m isequal to 1.

The present invention also relates to any resin based on PS-DVB, whichcan be obtained according to the process outlined above, characterizedby its general formula (V): ##STR11## in which X represents the oxygenor sulphur atom and m is equal to 1 or 2, R₁, R₂, R₃ and R₄ are,independently of each other, chosen from the methyl, ethyl, propyl,butyl, cyclohexyl and phenyl groups.

Preferably, in the formula (V), R₁, R₂, R₃ and R₄ each represent amethyl group and m is equal to 1.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The following preferred specific embodiments are,therefore, to be construed as merely illustrative, and not limitative ofthe remainder of the disclosure in any way whatsoever.

In the foregoing and in the following examples, all temperatures are setforth uncorrected in degrees Celsius and unless otherwise indicated, allparts and percentages are by weight.

Experimental Section

The resins are dried under a vacuum of about 4×10³ pascal.

1. Production of a First Resin of Formula (I) in which L Represents--CH₂ --.

(a) The PS-DVB resin used is a porous synthetic copolymer marketed bythe company Rohm and Haas: Amberlite XAD-4. The characteristics of thishighly crosslinked macroporous resin with a high specific surface are,according to the Rohm and Haas technical sheet:

Specific surface: 750 m² /g

Average pore diameter: 50 Å

Pore volume: 51%

(b) Functionalization of this resin with N-(chloromethyl)phthalimide.

10 g of pre-dried Amberlite X AD-4 resin are added to a solutioncomposed of 0.5 ml (0.0043 mol) of tin tetrachloride in 30 ml of1,2-dichloroethane and a solution of 6.7 g (0.0342 mol) ofN-(chloromethyl)phthalimide in 20 ml of 1,2-dichloroethane is then addedwith stirring at a temperature of 60° C. The reaction medium is keptstirring at reflux (82-84° C.) for 5 hours. After cooling to roomtemperature, the resin is filtered off and washed with1,2-dichloromethane and then with methanol. After drying under vacuum at60° C., 13.1 g of modified resin are obtained. IR spectrum: ν and δ bandof CO--N--CO at 1770 cm⁻¹ and 1710 cm⁻¹.

(c) Formation of the primary amine by hydrazinolysis.

12 g of the modified resin obtained are placed in 40 ml of absoluteethanol. 4.5 ml (0.092 mol) of hydrazine hydrate and 0.9 g (0.022 mol)of sodium hydroxide pellets are added to this suspension. The mixture ismaintained at reflux for 48 hours. After cooling to room temperature,the resin is filtered off and washed with ethanol and then treated withaqueous 5% by weight potassium hydroxide solution. The resin is thenwashed with water to neutral pH, with ethanol, with acetone and withmethanol. After drying under vacuum at 60° C., 11 g of resin areobtained.

IR spectrum: no more characteristic bands at 1770 cm⁻¹ and 1710 cm⁻¹ forthe phthalimide group --CO--N--CO--

Elemental analysis: 3.53% of nitrogen corresponding to 2.52 mmol of--NH₂ group/g of resin.

2. Production of a Second Resin of Formula (I) in which L Represents--CH₂ --.

(a) The pre-chloromethylated PS-DVB resin has the followingcharacteristics, determined by analysis:

Chlorine content: 19.32% by weight (Cl=5.44 meq/g of resin)

Specific surface: 22.5 m² /g

Average pore diameter: 20 Å

Pore volume: 69%.

(b) Functionalization of this resin with potassium phthalimide.

10 g (0.054 eq.Cl) of this chlorornethyl resin are placed in a solutionof 10.1 g (0.054 mol) of potassium phthalimide in 150 ml of anhydrousdimethylformamide (DMF) at a temperature of 50° C. and the suspensionthus obtained is left at this temperature for 24 hours. After cooling toroom temperature, the resin is filtered off and washed with DMF, withmethanol, with water, then again with methanol and finally with acetone.After drying under vacuum, 15.4 g of resin are obtained.

(c) Formation of the primary amine by hydrazinolysis.

The above phthalimidomethyl resin (15.4 g) is placed in a solution of6.6 ml (0.136 mol) of hydrazine hydrate in 150 ml of absolute ethanol,after addition of 1 g of sodium hydroxide pellets, and the mixture isstirred mechanically and maintained at reflux for 48 hours. The hotresin is then filtered off and washed with ethanol, then with water and,lastly, is treated with 400 ml of aqueous 10% by weight potassiumhydroxide solution. After this treatment, the resin is washed with wateruntil neutral, then with ethanol and finally with acetone. After dryingunder vacuum at 60° C., 10 g of resin are obtained.

Elemental analysis: N=5.46% by weight, i.e. a capacity of 3.92 mmol ofprimary amine function (--NH₂)/g of resin.

3. Production of a Third Resin of Formula (I) in which L Represents the--CH₂ --O--CH₂ --CH₂ -- radical.

The chloromethyl PS-DVB resin used is the same as that above in 2.a).

(a) Production of the primary amine resin.

A solution of 6.1 g of 60% sodium hydride (0.1525 mol) dissolved in 150ml of anhydrous THF (distilled over sodium) is prepared. A solution of9.8 ml (0.1633 mol) of ethanolamine in 100 ml of anhydrous THF is addedslowly to this solution under a nitrogen atnosphere. The reaction mediumis kept stirring at 20° C. for 1 hour and is then maintained at refluxfor 2 hours. After cooling to 20° C., 20 g of the chloromethyl resin areintroduced slowly. The reaction medium is brought to 70° C. withcontinued stirring and is maintained at this temperature for 48 hours.After cooling, the resin is filtered off and is then washed successivelywith water, with aqueous 5% by weight potassium hydroxide solution, thenwith water until neutral and finally with methanol. The resin is driedunder vacuum at 60° C. and 20.1 g of the primary amine resin bearing the--CH₂ --O--CH₂ --CH₂ -- spacer arm are obtained.

Elemental analysis: N=4.28% by weight, i.e. a capacity of 3.05 mmol ofprimary amine function (--NH₂)/g of resin.

4. Preparation of Vilsmeier Salts

(a) Preparation of tetramethylchloroformamidinium chloride

A solution of 3.2 ml (0.037 mol) of oxalyl chloride in 30 ml ofanhydrous carbon tetrachloride is added dropwise to a solution of 4.4 ml(0.037 mol) of tetramethylurea in 20 ml of anhydrous carbontetrachloride with stirring. The reaction medium is maintained atreflux, with continued stirring, until the evolution of gases (CO andCO₂) formed by the reaction has ceased. The CCl₄ is than eliminated bydistillation at atmospheric pressure. Tetramethylchloroformamidiniumchloride is obtained in the form of a white solid (6.23 g). This solidis placed in solution at 0° C. in 40 ml of anhydrous acetonitrile.

(b) Preparation of tetra-n-butylchloroformamidinium chloride.

5.5 g (0.055 mmol) of phosgene gas are bubbled over 2 hours into 10.4 g(0.037 mol) of tetra-n-butylurea with stirring, at a temperature of 80°C. When introduction of the phosgene is complete, the reaction medium ismaintained at 80° C. for 5 hours with stirring. The excess phosgene isremoved by evaporation under vacuum. The residue from this evaporationis tetra-n-butylchloroformamidinium chloride in the form of a whitesolid (12.45 g).

This solid is placed in solution at 0° C. in 40 ml of anhydrousacetonitrile.

5. Preparation of resins with a 1,1,3,3-tetramethylguanidine function ofgeneral formula (III) with R₁ =R₂ =R₃ =R₄ =methyl. Starting with theprimary amine resins of formula

(I) prepared above in points 1c), 2c) and 3a) and L represents --CH₂ --:resin A-109 manufactured by the company Purolite and having thefollowing characteristics:

Capacity determined by assay: 4.3 meq of primary amine functioning ofresin

Specific surface: 32.8 m² /g

Average pore diameter: 45 Å

Pore volume: 68.5%,

the resins of formula (III) are prepared usingtetramethylchloroformamidinium chloride, the characteristics of whichresins are disclosed in Table 1, according to the following procedure:

6.23 g (0.037 mol) of tetrarmethylchloroformamidinium chloride dissolvedin 40 ml of acetonitrile are added to 10 g of resin with a primaryamline function mixed with 8.7 ml (0.0625 mol) of triethylamine, underan anhydrous nitrogen atmosphere and at a temperature of 0° C. Thereaction medium is kept stirring for 4 days at a temperature of 20° C.and is then maintained at reflux for 1 hour. After cooling to 20° C.,the resin is filtered off and is washed with acetonitrile. It is thentreated with a 10% by weight solution of sodium hydroxide. It is thenwashed successively with water until neutral, with acetone, withmethanol and again with acetone. The resin is then dried under vacuum at60° C. to constant weight.

The characteristics of the resins prepared above are disclosed in Table1 below:

                                      TABLE 1                                     __________________________________________________________________________    Resin - NH.sub.2  Tetramethylguanidine (TMG) resins                           Example                                                                             Preparation                                                                           NH.sub.2                                                                          Elemental analysis                                                                           meq of TMG/g                                 No.   and L   meq/g                                                                             C %                                                                              H %                                                                              N %                                                                              Cl %                                                                             O% of resin                                     __________________________________________________________________________    1     1)      2.52                                                                              85.44                                                                            8.35                                                                             5.67                                                                             0.54                                                                             -- 1.35                                               L = --CH.sub.2 --                                                       2     2c)     3.92                                                                              81.25                                                                            7.60                                                                             6.35                                                                             0.79                                                                             4  1.51                                               L = --CH.sub.2 --                                                       3     3a)     3.05                                                                              77.73                                                                            8.40                                                                             6.98                                                                             2.42                                                                             4.46                                                                             1.66                                               L = --CH.sub.2 --O--                                                          (CH.sub.2).sub.2 -                                                      4     Purolite A109                                                                         4.3 81.68                                                                            3.26                                                                             8.40                                                                             0.71                                                                             0.94                                                                             2                                                  L = --CH.sub.2 --                                                       __________________________________________________________________________

EXAMPLE 5 Preparation of a Resin with a 1,1,3,3-tetra-n-butylguanidineFunction of Formula (III) in which L Represents --CH₂ --

The PS-DVB resin with a primary amine function obtained according to1a), b) and c) above is used in the following procedure:

12.45 g (0.0367 mol) of tetra-n-butylchloroformamidinium chloridedissolved in 40 ml of anhydrous acetonitrile are added to 10 g of thisaminomethyl resin (0.0252 mol of --NH₂ function) and 8.7 ml (0.0625 mol)of triethylamine, under an anhydrous nitrogen atmosphere and at atemperature of 0° C. The reaction medium is kept stirring at 20° C. for4 days and is then maintained at reflux for 1 hour. After cooling to 20°C., the resin is filtered off and is washed with acetonitrile and thentreated with aqueous 10% by weight sodium hydroxide solution. It is thenwashed successively with water until neutral, with acetone, withmethanol and again with acetone. After drying under vacuum at 60° C.,11.3 g of resin are obtained.

This resin has the following characteristics: Elemental analysis: N=4.7%by weight, i.e. a capacity of 1.1 mmol of tetrabutylguanidine function/gof resin

EXAMPLE 6 Use of the Resins of General Formula (III) with a GuanidineFunction, which are Obtained According to Examples 1, 2, 3 and 4 above,as Basic Catalysts

The activity of the guanidine resins of Examples 1 to 4 was tested inthe addition of a compound with a labile hydrogen to an activated olefinby reacting methyl 2-oxocyclopentanecarboxylate and methyl vinyl ketoneto give methyl 3-oxobutyl-2-oxocyclopentanecarboxylate by a Michaelreaction.

The tests are carried out in a three-necked round-bottomed flask fittedwith a mechanical stirrer and one neck of which is fitted with a Teflonseptum which allows samples of the liquid reaction medium to bewithdrawn during the reaction. These withdrawn samples are analysed bygas chromatography. The operations for loading the flask are carried outunder a nitrogen atmosphere.

The resin (0.5 g for each test) is introduced into the reactor with 140ml of anhydrous THF with 2.56 g (0.02 mol) of nonane used as internalstandard for the subsequent chromatography. The solution thus obtainedis thermostatically adjusted to 24° C. and stirred at 800revolutions/minute. After 30 min. the following reactants areintroduced: 2.86 g (0.02 mol) of methyl 2-oxocyclopentanecarboxylate and1.4 g (0.02 mol) of methyl vinyl ketone. The samples taken at determinedtimes are analysed directly on a Chrompack DB1 capillary column 15meters in length. The results are featured in Table 2.

                  TABLE 2                                                         ______________________________________                                               Yield as a % by mass of addition product                               Time in  Resin    Resin      Resin  Resin                                     min.     Example 1                                                                              Example 2  Example 3                                                                            Example 4                                 ______________________________________                                        10       11       2          12     4                                         20       20       6.5        25.5   7                                         30       26       9.5        40     13                                        60       44       19.5       62     25                                        80       51       24         72     31                                        160      70       38         93     49                                        240      76       52         100    59                                        320      89       61.5       --     72                                        ______________________________________                                    

These results show that the guanidine resin of Example 3, whichpossesses a spacer arm L=--CH₂ --O--CH₂ --CH₂ --, is markedly moreactive than the resins of Examples 1, 2 and 4 in which L represents a--CH₂ --.

The preceding examples can be repeated with similar success bysubstituting the generically or specifically described reactants and/oroperating conditions of this invention for those used in the precedingexamples.

The entire disclosure of all applicaitons, patents and publications,cited above and below, and or corresponding French application 95/14583,are hereby incorporated by reference.

From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

What is claimed:
 1. A resin of formula (V) ##STR12## wherein Xrepresents oxygen or sulphur and m is equal to 1 or 2, R₁, R₂, R₃ and R₄are, independently of each other, selected from the group consisting ofmethyl, ethyl, propyl, butyl, cyclohexyl and phenyl groups, and##STR13## is a polystyrene-divinyl benzene resin support.
 2. A resinaccording to claim 1, wherein R₁, R₂, R₃ and R₄ each represent a methylgroup and m is equal to
 1. 3. A resin of formula (I): ##STR14## wherein:##STR15## is a polystyrene-divinyl benzene resin support, and Lrepresents a radical of the formula (IV):

    --CH.sub.2 --(X--CH.sub.2 --CH.sub.2 --).sub.m --          (IV)

X representing oxygen --O-- or sulphur --S-- and m being equal to 1 or2.
 4. A resin according to claim 3, wherein X represents oxygen and m isequal to
 1. 5. A resin according to claim 3, wherein X representssulphur and m is equal to 1.